Foreach giving undefined variable error

10,877

Solution 1

You need to check to see if the entry name is set in your multidimensional array. Here is the long version because I was unaware of the short_open_tags option in PHP.

Code

<?
$entrees = array();
$entrees[0]['name']="Lamb";
$entrees[0]['description'] ="A small leg of lamb";
$entrees[1]['name']="Ham";
$entrees[1]['description'] ="Large thing of ham";

echo "<ul>\n";
foreach ($entrees as $entree) { 
 if(!empty($entree['name'])){
   echo "<li>";
   echo "<span class=\"food-name\">";
   echo $entree['name'];
   echo "</span>";
   echo "</li>\n";
 }
}
echo "</ul>";

?>

Output

<ul>
<li><span class="food-name">Lamb</span></li>
<li><span class="food-name">Ham</span></li>
</ul>

Update Learned something new thanks to @Arjan - the original code you had with the [short_open_tags][1] should also work with the if statement provided they are enabled in your build. In my testing they threw an error as my test machine uses an older build of PHP. After rebuilding they do work by default.

<?=$entree['name']?>

According to the manual in this usage the = sign means echo() and is enabled by default in PHP 5.4.1. Upon searching through Google because their searches use the operators differently I was unable to find a link since I did not know the name for the usage. If you're programming with a team of developers make sure to use the same agreed upon tag styles as the rest of the team.

Solution 2

You need to set short_open_tag to On in php.ini. That fixed it for me with no additional code.

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Dylan Buth
Author by

Dylan Buth

Updated on June 04, 2022

Comments

  • Dylan Buth
    Dylan Buth 7 months

    Bare in mind that it's late where I am so this may just be a very simple solution that I am overlooking.

    I have this foreach statement:

      <? foreach ($entrees as $entree) { ?>
           <li>
               <span class="food-name">
                   <?=$entree['name']?>
               </span>
           </li>
      <?}?>
    

    That gives an Undefined variable error for $entree.

     A PHP Error was encountered
    
     Severity: Notice
    
     Message: Undefined variable: entree
    
     Filename: views/welcome_message.php
    
     Line Number: 9
    

    I tried print_r($entrees); and the result was

     Array ( [0] => Array ( [name] => Lamb [description] => A small leg of lamb ) [1] => Array ( [name] => Ham [description] => Large thing of ham ) ) 1
    

    Again, this may be something stupid simple but I've been trying to 30 min and can't get it to work for the life of me. Thanks in advance for the help.

  • Dylan Buth
    Dylan Buth over 9 years
    It sort of works. It repeats the first result. What is this tArr? Can't find it on google.
  • AbsoluteƵERØ
    AbsoluteƵERØ over 9 years
    It's just a placeholder short for temporary array. We're assigning the key to $entree and the value array associated with the $key to $tArr.
  • AbsoluteƵERØ
    AbsoluteƵERØ over 9 years
    Eh, I've updated my code. It should be easier for you to follow since it's the style you're used to.
  • Dylan Buth
    Dylan Buth over 9 years
    I was just renaming variables as a test. Copied the wrong error message.
  • AbsoluteƵERØ
    AbsoluteƵERØ over 9 years
    That works. Some of my accounts are on Dreamhost and they have some strange errors they've compiled in from time to time. "Error: You are not a Jedi." Their server names are strange too... things like eggnog.
  • Dylan Buth
    Dylan Buth over 9 years
    When I tried <? echo $entree['name']; ?> it showed in DOM as a comment. When I did same thing with <?php ?> I got the same undefined variable error.
  • AbsoluteƵERØ
    AbsoluteƵERØ over 9 years
    I've added an if statement to make sure there is a variable there. If there isn't in your multidimensional array it will throw an undefined index error. The DOM is the Document Object Model. It might have said that if there aren't any <ul> or <ol> tags.
  • Dylan Buth
    Dylan Buth over 9 years
    I am confused by your code though. It's great that is works but I don't understand it. Like the \n and class=\"food-name\">"
  • AbsoluteƵERØ
    AbsoluteƵERØ over 9 years
    Since I've putting everything into quotes I have to escape the same quotes. The \n is a new line character (to make it easier to read in HTML).
  • Dylan Buth
    Dylan Buth over 9 years
    So could the same be accomplished with class='food-name' ?
  • AbsoluteƵERØ
    AbsoluteƵERØ over 9 years
    Yes. As long as the quotes do not match the container they do not need to be escaped.
  • Arjan
    Arjan over 9 years
    Actually, <?=$foo;?> is the same as <?php echo $foo; ?> if short_open_tags are enabled.
  • AbsoluteƵERØ
    AbsoluteƵERØ over 9 years
    @Arjan Thanks for that. I tried searching for the equal signs but Google returns no results (probably by design). google.com/…
  • user2580401
    user2580401 over 4 years
    OMG this exact problem has caught me so off guard. Thanks for the tip! (Even if it's been 4 years since you posted it). To other googlers: an alternative to this solution is to replace actual short open tags (<?) with normal ones (<?php) in your code.